/*
 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 *
 */

package com.sun.imageio.plugins.png;

import java.io.IOException;
import java.util.Locale;
import java.util.Iterator;
import javax.imageio.ImageReader;
import javax.imageio.spi.ImageReaderSpi;
import javax.imageio.metadata.IIOMetadataFormat;
import javax.imageio.metadata.IIOMetadataFormatImpl;
import javax.imageio.stream.ImageInputStream;

public class PNGImageReaderSpi extends ImageReaderSpi {

  private static final String vendorName = "Oracle Corporation";

  private static final String version = "1.0";

  private static final String[] names = {"png", "PNG"};

  private static final String[] suffixes = {"png"};

  private static final String[] MIMETypes = {"image/png", "image/x-png"};

  private static final String readerClassName =
      "com.sun.imageio.plugins.png.PNGImageReader";

  private static final String[] writerSpiNames = {
      "com.sun.imageio.plugins.png.PNGImageWriterSpi"
  };

  public PNGImageReaderSpi() {
    super(vendorName,
        version,
        names,
        suffixes,
        MIMETypes,
        readerClassName,
        new Class[]{ImageInputStream.class},
        writerSpiNames,
        false,
        null, null,
        null, null,
        true,
        PNGMetadata.nativeMetadataFormatName,
        "com.sun.imageio.plugins.png.PNGMetadataFormat",
        null, null
    );
  }

  public String getDescription(Locale locale) {
    return "Standard PNG image reader";
  }

  public boolean canDecodeInput(Object input) throws IOException {
    if (!(input instanceof ImageInputStream)) {
      return false;
    }

    ImageInputStream stream = (ImageInputStream) input;
    byte[] b = new byte[8];
    stream.mark();
    stream.readFully(b);
    stream.reset();

    return (b[0] == (byte) 137 &&
        b[1] == (byte) 80 &&
        b[2] == (byte) 78 &&
        b[3] == (byte) 71 &&
        b[4] == (byte) 13 &&
        b[5] == (byte) 10 &&
        b[6] == (byte) 26 &&
        b[7] == (byte) 10);
  }

  public ImageReader createReaderInstance(Object extension) {
    return new PNGImageReader(this);
  }
}
